köken: Late 17th century, from Dutch berebery (1612), beriberij (1631), possibly through French béribéri (1665). The Dutch is either from Portuguese berebere (1568) or directly from a language of Southeast Asia. The ultimate origin is usually identified as Sinhalese බැරි (bæri, “weakness, incapacity”). An older theory connects it with Malay biri-biri (“sheep”, a supposedly dull and weak animal).